1. Field of the Invention
The present invention relates to a machine tool, and more particularly, to a machine tool equipped with a member adapted to scrape out chips built up on part of the machine tool.
2. Description of the Related Art
In a machine tool, as a method for scraping out chips built up on part of the machine, it is common practice to use a wiper or a scraper plate. Regarding chips which cannot be scraped out by a wiper, a method is available which washes away the chips by supplying lubricating oil to a space formed for use as a flow path for lubricating oil. The conventional technique described above is disclosed, for example, in Japanese Patent Application Laid-Open Nos. 5-228782 and 2004-106066.
With the technique disclosed in Japanese Patent Application Laid-Open No. 5-228782 described above, in order to completely scrape out the chips built up on the machine, it is necessary to move a table to the farthest end of a motion range. In actual machining, the table is rarely moved to the farthest end of the motion range, and it is very likely that chips will just keep on building up.
Also, the technique disclosed in Japanese Patent Application Laid-Open No. 2004-106066, according to which the wiper is placed in contact with a sliding surface, is expected to achieve the effect of keeping out chips. However, to remove chips which have once entered a space on the inner side of the wiper, there is no way but to wash away the chips by lubricating oil, which is disadvantageous in that a complicated large-scale structure is required. Also, even if lubricating oil is present, abrasion of the wiper due to pinching of chips or due to sliding is unavoidable and periodic parts replacement is necessary. If periodic parts replacement is neglected, there is a problem in that a clearance will be produced, allowing chips to enter.